高温合金GH4169超声喷丸强化表征与热影响分析

蔡晋; 任晓光; 姚伟

doi:10.3969/j.issn.2095-1248.2025.01.003

沈阳航空航天大学学报 ›› 2025, Vol. 42 ›› Issue (1) : 25 -35. DOI: 10.3969/j.issn.2095-1248.2025.01.003

航空宇航工程

高温合金GH4169超声喷丸强化表征与热影响分析

蔡晋 ¹ ,
任晓光 ¹ ,
姚伟 ²

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Characterization and thermal impact analysis of ultrasonic peening strengthening of superalloy GH4169

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摘要

针对改善高温合金GH4169表面完整性的问题，对高温合金GH4169试样进行了超声喷丸和热暴露试验。首先，进行了覆盖率为98%~125%、喷丸强度为0.15 A和0.25 A的超声喷丸试验。然后，对试样分别进行了250、400、550 ℃的1 h和10 h的热暴露试验，最后研究了超声喷丸对高温合金GH4169表面粗糙度、硬度、微观形貌和残余压应力的影响，并分析了热暴露后残余压应力的变化。研究结果表明，经超声喷丸后，高温合金GH4169表面发生塑性变形，表层硬度显著提高。近表层晶粒细化明显，晶粒尺寸由表层至深度呈梯度分布，并在表层引入残余压应力。当喷丸强度从0.15 A提升至0.25 A时，晶粒细化程度提升了29%。高温合金GH4169经过高温热暴露后，表层残余压应力发生热松弛，最大松弛速率发生在热暴露初期阶段，之后便趋于稳定，与热暴露时间无关。热暴露温度越高，近表层残余热松弛越剧烈，最大残余压应力深度位置越大。

Abstract

To address the issue of improving the surface integrity of superalloy GH4169，ultrasonic peening and thermal exposure tests were conducted on superalloy GH4169 specimens.The specimens were first subjected to ultrasonic peening tests with a penning coverage of 98%~125% and peening intensity of 0.15 A and 0.25 A. Then the specimens were thermally exposed at 250 °C，400 °C and 550 °C for 1 hour and 10 hours respectively. Finally，the effects of ultrasonic peening on the surface roughness，hardness，microstructure and residual compressive stress of superalloy GH4169 were analyzed，as well as the changes in residual compressive stress after thermal exposure. The results indicate that after ultrasonic peening，the surface of superalloy GH4169 undergoes plastic deformation and the surface hardness significantly increases.The grain refinement in the near-surface layer is significant，and the grain size shows a gradient distribution from the surface layer to the depth，introducing residual compressive stress in the surface layer.Compared to 0.15 A，the peening intensity of 0.25 A increases the grain refinement by 29%.After high-temperature thermal exposure，the residual compressive stresses on the surface of superalloy GH4169 undergo thermal relaxation，with the maximum rate occurring at the initial stage of thermal exposure，after which it tends to stabilize and becomes independent of the duration of thermal exposure.The higher the thermal exposure temperature，the more intense the relaxation of the near-surface residual stress and the greater the depth at which the maximum residual compressive stress is located.